Be careful signing up for the subscription. You only get a10% discount but will have to pay for shipping, which ends up being more expensive than just ordering when you need the product(s) again next. You'll also be billed before receiving a reminder, and if you attempt to cancel or postpone that month's order they'll charge you anyway.
You could always call customer service multiple times, but they'll just promise you they'll refund it / cancel the shipment / get back to you (looking at you Spencer and Carlos), but don't rely on that either.
Dr. Schulze's / American Botanical is a predatory subscription service with non existent customer service. Do business with them at your own risk.